Savannah Guthrie, host of NBC's "Today," asked Clinton if she was nervous about the movement in those polls.

"No, I'm not nervous at all,'' Clinton responded. "I'm working hard, and I intend to keep working as hard as I can until the last voter or caucusgoer expresses an opinion. I'm excited about where we are."

Clinton further noted the disagreements between her and Sanders on certain topics, including healthcare and gun safety.

"I think we're in that stage of a campaign where we've each been introducing ourselves, we've been talking about our particular views on issues, and now it's time to draw some contrasts," she said.